The present invention relates to the processing of frozen vegetables. In particular, it relates to a method of processing frozen vegetables having a delicate structure in a manner which protects the structure and reduces breakage during processing and subsequent handling.
The demand for high quality, nutritious, and aesthetically pleasing frozen foods has increased dramatically in recent years. Consumers demand frozen foods which are pleasing to the eye, are high in nutrient value, and are conveniently packaged. Manufacturers of frozen foods have found it necessary to improve product quality and at the same time reduce costs to effectively compete in the increasingly competitive frozen food market.
An example of a frozen vegetable which is very popular with consumers is frozen broccoli. The portion of the broccoli plant which has the greatest appeal to consumers is the delicate broccoli floret. Broccoli florets have a fragile structure and are susceptible to breakage during processing, handling and shipping.
One technique currently used for processing a variety of frozen vegetables is the individual quick freeze ("IQF") method. IQF vegetables are separated and frozen individually by a variety of methods such as spreading the vegetables out on sheets and placing the sheets in a freezer, or by agitating the vegetables during freezing. Consumers have long preferred IQF vegetables over vegetables which are frozen collectively in a block.
Frozen IQF vegetables do not stick together in a storage container. Consumers prefer IQF vegetables because any size portion can be prepared, and because the vegetables are free flowing and are easy to remove from the package.
A patent which illustrates the preparation of IQF vegetables is Fallon et al. U.S. Pat. No. 3,868,470. The Fallon et al. patent discloses a method of applying a viscous coating containing a seasoning to IQF vegetables. Presently, manufacturers of IQF vegetable products apply an ice glazing to some vegetables to preserve the freshness of the product. Knowles U.S. Pat. No. 2,385,140 illustrates that it is known in the art to apply an ice coating to the surface of a vegetable in order to prevent oxidation and to protect the surface from exposure to microorganisms, such as fungi.
The method disclosed in Knowles is a process of preparing vegetables including the steps of freezing a vegetable, placing the frozen vegetables on a shaker, applying a quantity of water while shaking the vegetables to form an ice glaze, and then refreezing the glazed vegetable. The specific vegetables mentioned in this reference are peas, beans, and any vegetable which may be moved along by the action of a shaker. See Col. 4, lines 53-57.
The handling method disclosed in Knowles U.S. Pat. No. 2,385,140 for ice glazing vegetables is not suitable for handling broccoli florets because the shaking action of the screen fractures the delicate floret structure. The shaking action also causes an excessive amount of fines loss. "Fines" for purposes of this disclosure are defined as portions of the floret structure which break off during processing.
Manufacturers of IQF broccoli have found that by using current handling techniques, the floret structure is damaged, and a significant amount of fines are generated during packaging, transport, and handling. Before the present invention, manufacturers have not discovered methods to preserve the floret structure and reduce the amounts of fines generated during the preparation of frozen broccoli florets.